Coroutines Test 入門 / Android Test Night #8

Transcript

1. Android Test Night #8 2023/03/10 Coroutines Test 入門
2. • Kenji Abe • @STAR_ZERO • Google Developers Expert for Android, Kotlin • DeNA Co., Ltd.
3. // build.gradle dependencies { // ... testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.6.4") }
4. supsend関数のテスト
5. class Sample { suspend fun run(): String { return "hoge" } }
6. class SampleTest { @Test fun testRun() = runTest { val sample = Sample() val result = sample.run() assert(result == "hoge") } }
7. class SampleTest { @Test fun testRun() = runTest { val sample = Sample() val result = sample.run() assert(result == "hoge") } }
8. • runBlockingのようなもの • delay関数はすべてスキップされる ◦ Vertial Timeを制御することができる • TestScopeが使用される runTest
9. TestDispatchers
10. • StandardTestDispatcher ◦ runTestデフォルト ◦ TestCoroutineSchedulerを使用するシンプルなDispatcher • UnconfinedTestDispatcher ◦ Dispatchers.Unconfinedのようなもの ◦ トップレベルのlaunch/asyncがすぐに実行される TestDispatchers
11. class SampleTest { @Test fun testRun() = runTest { val sample = Sample() val result = sample.run() assert(result == "hoge") } }
12. @Test fun test() = runTest { var result = 0 launch { result = 1 } assert(result == 1) }
13. @Test fun test() = runTest { var result = 0 launch { result = 1 } assert(result == 1) } ❌ Failed
14. @Test fun test() = runTest { var result = 0 launch { result = 1 } assert(result == 1) } ① ② ③
15. @Test fun test() = runTest { var result = 0 launch { result = 1 } runCurrent() assert(result == 1) } ✅ Success
16. @Test fun test() = runTest { var result = 0 launch { result = 1 } runCurrent() assert(result == 1) } ① ② ③ ④
17. @Test fun test() = runTest { var result = 0 launch { delay(1000) result = 1 } runCurrent() assert(result == 1) }
18. @Test fun test() = runTest { var result = 0 launch { delay(1000) result = 1 } runCurrent() assert(result == 1) } ❌ Failed
19. @Test fun test() = runTest { var result = 0 launch { delay(1000) result = 1 } runCurrent() assert(result == 1) } ① ② ③ ④ ⑤
20. @Test fun test() = runTest { // ... advanceUntilIdle() // または advanceTimeBy(1001) assert(result == 1) } ✅ Success
21. @Test fun test() = runTest(UnconfinedTestDispatcher()) { var result = 0 launch { result = 1 } assert(result == 1) }
22. @Test fun test() = runTest(UnconfinedTestDispatcher()) { var result = 0 launch { result = 1 } assert(result == 1) } ✅ Success
23. Mainスレッド対応
24. class Sample { suspend fun run(): String = withContext(Dispatchers.Main) { "hoge" } }
25. @Test fun testRun() = runTest { val sample = Sample() val result = sample.run() assert(result == "hoge") }
26. @Test fun testRun() = runTest { val sample = Sample() val result = sample.run() assert(result == "hoge") }
27. @Before fun setUp() { Dispatchers.setMain(StandardTestDispatcher()) } @After fun tearDown() { Dispatchers.resetMain() }
28. Flowのテスト
29. class Sample { val flow = MutableSharedFlow<Int>() suspend fun emit(value: Int) { flow.emit(value) } }
30. @Test fun test() = runTest(UnconfinedTestDispatcher()) { val sample = Sample() val result = mutableListOf<Int>() val job = launch { sample.flow.toCollection(result) } assert(result.size == 0) sample.emit(1) assert(result.size == 1) assert(result.first() == 1) job.cancel() }
31. @Test fun test() = runTest(UnconfinedTestDispatcher()) { val sample = Sample() val result = mutableListOf<Int>() // ... }
32. @Test fun test() = runTest(UnconfinedTestDispatcher()) { val sample = Sample() val result = mutableListOf<Int>() val job = launch { sample.flow.toCollection(result) } // ... }
33. @Test fun test() = runTest(UnconfinedTestDispatcher()) { val sample = Sample() val result = mutableListOf<Int>() val job = launch { sample.flow.toCollection(result) } // ... }
34. @Test fun test() = runTest(UnconfinedTestDispatcher()) { // ... val job = launch { sample.flow.toCollection(result) } assert(result.size == 0) // ... }
35. @Test fun test() = runTest(UnconfinedTestDispatcher()) { // ... val job = launch { sample.flow.toCollection(result) } sample.emit(1) // ... }
36. @Test fun test() = runTest(UnconfinedTestDispatcher()) { // ... sample.emit(1) assert(result.size == 1) assert(result.first() == 1) job.cancel() }
37. @Test fun test() = runTest(UnconfinedTestDispatcher()) { // ... val job = launch { sample.flow.toCollection(result) } // ... job.cancel() }
38. @Test fun test() = runTest(UnconfinedTestDispatcher()) { // ... backgroundScope.launch { sample.flow.toCollection(result) } // ... // job.cancel() }
39. Turbine （時間の都合上省略...） https://github.com/cashapp/turbine
40. まとめ
41. • runTest • StandardTestDispatcher / UnconfinedTestDispatcher • Dispatchers.setMain • backgroundScope まとめ
42. ありがとうございました